A molecule with a name so long it's almost impossible to spell holds great promise for people with multiple sclerosis (MS), Australian researchers say.

Australian researchers are about to begin a large-scale test of a drug that could thwart the progression of multiple sclerosis (MS).

Monash University researchers believe a small molecule may help protect nerve fibres in the brain, spinal cord and optic nerves, and could even aid their repair.

It's hoped the molecule could one day help patients with Secondary Progressive MS, a stage when the disease steadily worsens and can cause muscular spasms and problems with co-ordination, weakness and limb function.

MS occurs when the body's immune system attacks its own tissues. In the case of MS, this immune system malfunction destroys myelin - the fatty substance that coats and protects nerve fibres in the brain and spinal cord.

Eventually, the disease can cause the nerves themselves to deteriorate or become permanently damaged.

But Monash University neuroscientist Dr Steven Petratos believes the molecule - Diiodothyropropionic acid - could prove a game-changer for MS sufferers.

He says existing drugs can moderate the disease and treat inflammation associated with it, but they don't address the degenerative aspect of MS.

"It has the advantage of being able to cross the blood-brain barrier to target affected cells in the brain, a limitation of existing treatment," Dr Petratos says.

"The drug that we've identified may have a significant benefit in changing the course of MS progression primarily from the aspect of protection of the central nervous system, as well as enhancing repair."

The study will test for possible side effects of the drug and any toxic outcomes. As for its potential for repair, the drug will need be tested long-term because nerve repair would take years.

MS Research Australia has contributed $70,000 towards the study.

The molecule has been patented and researchers are already negotiating with a potential commercial partner to further develop and test the drug in clinical trials.